Justification:
Prior to the 1980s, recorded from multiple sites across the central and western archipelago, but currently only known from western Fernandina and southwestern Isabela after targeted surveys. Based on total reduction in extent of occurrence over the past thirty years, mean population decline estimated at 30 to 50% per ten year interval over that period, with presumed cause of decline (El Niño) persisting and probably exacerbated by climate change. This species assessed as Vulnerable.

Taylor (1945) reported E. galapagensis as rare and uncommon at Post Office Bay, Floreana, and common at Academy Bay, Santa Cruz. Additionally, Wellington (1975) reported E. galapagensis as especially abundant at depth around Caleta Iguana (Isabela). Since then, it has been collected from several sites off western Fernandina in 2004 and 2007, and at Caleta Iguana in 2007 (Graham et al. 2007).

E. galapagensis has been reported to occur at depths of 27 to 55 m (Taylor 1945). This species is easy to recognize, in part because it has a maximum size of at least 85 cm frond length and is the sole known member of the cold-water order Laminariales occurring in the Galápagos Islands. E. galapagensis typically grow in groups; juveniles through adults were observed at all sites recorded in 2007. Individuals have been found as shallow as 12 m but populations appear to increase in density and size with depth, to at least 60 m when suitable substrata are available (Graham et al. 2007). The conspicuous sporophyte alternates with a microscopic phase.

Presumably El Niño and climate change. Ecosystem interactions involving these two factors appear to have caused widespread decline in algal populations because of an increase in density of grazing sea urchins and other herbivores, following overexploitation of predators along with ENSO disturbances.